At 5-on-5 there hasn't been a huge difference in Crookshank and Kelly's AHL production...
Crookshank: 46 points in 127 games [.36 per game], 36 primary points
Kelly: 35 points in 123 games [.28 per game], 28 primary points
Normalized over a 76 game AHL season that's about a 5 point gap. So not much.
What is really going to hurt Crookshank is his lack of defensive utility. There's just not a ton of undersized, offense only, agitator types in the league. Mikey Eyssimont. Nick Cousins. Ryan Lomberg. So it's not impossible to make it, but it's a hard road.